Dual completion apparatus



Dec. 24, 1963 c. QBROWN DUAL COMPLETION APPARATUS 5 Sheets-Sheet 1 Filed May 2, 1955 m E m m 5mm /WA C XZ 0 f w 47%/ m Y C B 3 Sheets-Sheet 2 C. C. BROWN DUAL COMPLETION APPARATUS M ,d/ T M am@ Z- W N W /f m g 1 5,/ 1 I C. M, w/ M Il m m .w Wl I* www C IIL ,www ,D J t 5 6 M m www w j J a ab mxiwmw//.M n v @NNM Lv; wv/Nvv/MM 70M .x 7 ww M 4/ j w i.. .d E |(M. lt,...

Filed May 2, 1955 M/ WW Dec. 24, 1963 c. c. BROWN DUAL COMPLETION APPARATUS Filed May 2, 1955 5 Sheets-Sheet 3 NVENTR.

United States Patent O 3,115,185 DUAL COMPLETION APPARATUS Cicero C. Brown, Houston, Tex., assignor to Brown Oil Tools, Ine., Houston, Tex., a corporation of Texas Filed May 2, 1955, Ser. No. 505,095 4 Claims. (Cl. 166-119) This invention relates to new and useful improvements in well apparatus and methods of setting a plurality of tubing strings in a well bore.

The invention relates especially to a dual production well apparatus which is adapted to be lowered into the well bore or casing after the positioning of a lower well packer and an upper well packer so as to obtain production from several well formations through separate tubing strings.

An important object of this invention is to provide a new and improved well apparatus having a pair of tubing strings connected thereto, wherein the strings are adapted to be run separately of the well packers so that said strings may be positioned within the well or removed therefrom independently of the well packers; said apparatus also including means for running and moving each of the tubing-strings independently of each other, whereby the disadvantages incident to simultaneous handling of a double string of welll tubing are obviated.

Another object of this invention is to provide a new and improved well apparatus which is adapted to be used in a well casing or pipe in conjunction with a plurality of well packers, wherein the packers are adapted to be set in the well casing or pipe prior to the positioning of said apparatus therein, and wherein said apparatus has means for attaching same to the upper one of said packers upon a nonrotative downward movement of said apparatus relative to said upper one of the packers.

Another object of this invention is to provide a new and improved method of lowering a plurality of tubing strings into a well bore wherein a plurality of well packers are initially set in the well bore in spaced relationship, and thereafter a well apparatus is lowered into the well bore for establishing fluid communication from the area between the packers to one tubing string and from the area below both packers to another tubing string.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and where- FIGURE 1 is a diagrammatic view illustrating the well apparatus of this invention in use with a pair of well packers which have been previously set in a well casing or pipe.

FIGURES 2A and 2B are sectional views, with a portion thereof in elevation, illustrating the apparatus of this invention in a seated position on the upper packer, with FIGURE 2A illustrating the upper portion thereof and FIGURE 2B illustrating the lower portion thereof.

FIGURE 3 is a view, partly in elevation and partly in section, illustrating the details of the upper portion of the apparatus of FIGURE 2A.

FIGURE 4 is a view, partly in elevation and partly in section, illustrating the lowering of the upper packer into the well bore.

FIGURE 5 is a view, parti-y in elevation and partly in section, illustrating a modification of the apparatus of FIGURES 2A and 2B.

In the drawings, the letter A designates generally the new and improved well apparatus of this invention which is adapted to be lowered into position in a well bore or Patented Dec. 24, 1963 ICC casing C for use in conjunction with well packers B and D. The packers B and D are of the type which are adapted to be set in the well pipe or casing C by a lowering tool which is removable from the packer so as to leave the packer in the wel-l pipe or casing in a set position with an open bore therethrough. The packer D is generally set above the well formation F While the packer B is generally set above an upper formation F and, of course, suitable perforations P and P are provided in the casing C to permit uid ow between the formations and the interior of the casing C. The apparatus A of this invention is adapted to be lowered into the casing C after the packers B and D have been set therein so as to establish uid communication from the formation F below the packer D to the tubing string 10 which extends to the surface of the well and to also establish iiuid communication from the well formation F between the packers D and B to the other tubing string 12 which extends to the surface of the well, as will be hereinafter explained.

The details of the well apparatus of this invention are shown in FIGURES 2A and 2B, wherein such apparatus is illustrated in its connected or seated position with respect to the wire line packer B. The well apparatus A includes a substantially cylindrical upper body 14 (FIG- URE 2A) which is provided with longitudinal bores or passages 16 and 17 which extend from the upper end thereof to the lower end thereof. The intermediate portion of the bore 16 is provided with an annular inwardly extending inclined shoulder 16a and the bore 17 is provided with a similar inwardly extending inclined annular shoulder 17a, each of which is provided for the releasable attachment of plug or choke (not shown).

The upper portion of the bore 16 is constructed for receiving and detachably connecting thereto the lower end of the tubing string 10 which extends to the surface of the well. The external surface of the tubing string 10 has threads 10a (FIGURE 3) formed thereon near its lower end for coaction with threads 20a. formed on the interior of a nut 2t). The nut 20 is made of metal or other expansible material and is a split ring which is prevented from rotating by a pin 21 which is threaded in the body 14 and which extends into the split or slot of the nut 20. The external surface of the nut 20 is tapered or inclined downwardly and outwardly at substantially the same angle as the outer surface of the recess 24 in which the nut 2t) is positioned so that as the nut 20 moves downwardly in the recess 24, the nut 2i) can be expanded to an increased inner diameter. Thus, as the lower end of the tubing string 10 enters the bore 16 and the threads 10a contact the threads 20a, the nut 20 is expanded as it slides downwardly to the enlarged lower portion of the recess 24 so as to permit the threads 10a to slide downwardly relative to the threads 20a without requiring any rotation of the tubing string 10. Once the threads 20a and 10a are thus engaged, the tubing string 10 cannot be disconnected from the nut 2t) or the body 14 by a nonrotative upward pull on the tubing string 10, because any upward movement of the tubing string 10 carries the nut 2t) upwardly therewith and wedges same into tight threaded engagement with the threads 10a. When it is desired to release the tubing string 1t), such string 10 is rotated to the right, assuming the threads 10a and 20a are left-hand threads, whereupon, the tubing string 10 is backed out upwardly and can thereafter be removed by raising upwardly on the tubing string 10 at the surface of the well.

It should be noted that an annular fluid seal 25 is provided in the bore 16 Ifor sealing engagement with the external surface of the lower end of the tubing string 10 when it is in its connected position. Such seal 25 may be formed of rubber or other resilient sealing material so that when the tubing string 10i is in its connected or seated position, fluid flow from the bore 16 of the body 14 is prevented from passing around the exterior of the tubing string 10.

The tubing string 12 is also detachably connected to the body 14 and such detachable connection is effected by positioning such string 12 in the upper end `of the passage 1'7 of the body 14 FGURB 3. The tubing string 12 'carries lon its lower end an annular `seal 27 wh-ich is illust-rated as a chevron packing, but may be any type of resi-lient sealing material which is adapted to close of fluid ow around the lower end of the tubing string 12 so that all ilu-id flow from the bore 17 is directed upwardly through the interior of the tubing string 12.

Above the seal 27, the tubing string 12 is provided with an upwardly and inwardly tapered conical portion 28 upon which is disposed a nut 219 which has threads 29a formed on the external surface thereof. The nut 29 is a split ring which is made of metal or other expansible material and such nut 29 is held against rotation by a pin 30 which extends from the string 12 into the split or slot of the nut 29. The inner surface 29h of the nut 29 has Isubstantially the same inclination or taper as the tapered or conical surface 21S. As the tubing string 12 is lowered into the bore 17, the nut 29 rides at the upper portion of the tapered section 28 and is in `its -inner or retracted position so as to permit the relative downward movement tof the nut 29 with respect to the threads 17b wil-lout requiring any rotation of the tubing string 12. However, the tubing -string'cannot fbe removed from the bore 17 by pulling upwardly on the string 12 without any rotation, because the surface 28 coacts with lthe surfaces 2911 to urge or expand the nut 29 outwardly and to prevent any upward movement fby reason of the tight interengagement of the threads 29a and 17h. When it `is desired to remove the tubing string 12 from the bore 17, the string 12 is rotated to the right, assuming the threads 29a and 17b are left-hand threads, and the pin 30 imparts the rotation of the string 12 to the nut 29. The nut 29 can thus be threaded upwardly relative to the threads 17b ,so as to remove the nut 29' with the tubing string 12 from the bore 17. It can thus be seen that both the tubing string and the tubing string 12 are provided with automatic bottom type of connecting means. It will be understood, however, that other types of detachable connections can fbe provided.

The upper end of the body 14 is provided with a downwardly and inwardly inclined `surface 14a which slopes downwardly and inwardly toward the upper end of the bore 16 so that when the tubing string 1l) is lowered to connect same to the body 14, the lower end of the string 10 is guided into the bore 16 by means of the guide surface 14a. The tubing string 12 is likewise guided into the bore 17 by the engagement of the lower end thereof with the guide surface 141) at the upper end of the body 14 which is sloped downwardly towards the upper end of the passage 17. It will be noted that a ridge or edge 14C is formed between the guidel surfaces 14a and 14h. Preferably the surfaces are formed at substantially 45 angle so that the concave slope towards each of the passages 16 and 17 is a-t la substantially 45 angle. It will be appreciated that the tubing string 12 is ordinarily lowered into position when the string 10` is connected to the body 14 so that there is no danger of lowering the tubing string 12 into the wrong passage in the body 14. Similarly, if the string 10 is disconnected, the string 12 is ordinarily left in a connected position so that the string 10 can be reconnected in the proper passage 16. An outer tubular pipe 35 is connected to the lower end of the body 14 by threads 35a or any other suitable means so that the pipe 35 forms an extension of said body 14 and extends downwardly from the body 14; as will be explained, such pipe 35 extends through the bore of the upper packer B. An inner pipe 36 is disposed within the outer pipe 35 and it has a threaded `connection with the body 14 by means of its threads 36a which engage with threads 16b disposed in the lower end of the bore 16. The inner pipe 36 thus is positioned at one side of the bore 35b of the outer pipe 35 at its point of connection with the bore 16. The lower portion of the bore 35h of said pipe is reduced, yforming an inwardly ldirected shoulder 35e (FIG. 1) which is spaced from the lower end of the pipe 35' a suicient distance that engagement yof the inner pipe with the shoulder tends to displace the pipe 36 away from the contact with the bore 3511 near its lower end whereby the pipe 35 is substantially concentrically positioned as the pipe 36 leaves the lower end of the .outer pipe 35 (FIGURES l and ZB) so as to facilitate the positioning of the lower end of the inner pipe 36 within the bore of the lower packer D.

As will be explained, the packer B is of the type which is maintained in a set position by a differential well iiuid pressure actingthereon and to assure the application of the differential fluid press-ure above fand below the packer B, the :outer pipe 3'5 is provided with :annular seals 37 and 38` which may be formed of any suitable packing material which is adapted to seal with the bore or inner surface of the packer B. Below the seals 37 and 38, the external surface of the outer pipe 35 is formed with threads 39 which 'are specially constructed with an inclined lower surface 39a and a substantially laterally extending upper surface 39h, the purpose of which will be hereinafter explained. It will be observed that the lower end of the outer pipe 35 terminates just below the packer B (FIG- URES l and 2B) so that the iluid from the formation F below the packer B is directed upwardly through the interior of the pipe 35 and around the inner pipe 35 to the bore 17 and tubing `string 12. The inner pipe 36 extends downwardly thnough the bore of the packer D and therefore establishes fluid communication from the well format-ion F to the bore 16 and then to the tubing string 10.

The packers B and D may be constructed in accordance with the disclosure in my U.S. Patent Number 2,739,651, wherein a packer is disclosed which is adapted to be set by a tool lowered on a wire line. Also, as illustrated in FIGURE 2B, the packer B is of a type which is adapted to be set by a differential in the well uid pressure, as is true of the packer disclosed in my aforesaid patent, but the construction of the packer B is somewhat modied as compared to the particular embodiment illustrated in the said patent. Such packer B includes an annular slip body or housing 49 which has friction springs 47 thereon for constant frictional contact with the casing C. The body 40 also carries the usual slips 41 which are adapted to be moved outwardly in opening 45a into gripping engagement with the well casing or pipe C. An annular slip expander or cone 42 extends within the bores of the slips 41 and is adapted to move downwardly relative to the slips 41 for effecting such urging of the slips into gripping engagement with the casing of pipe C. The slip expander 42 has a plurality of retaining pins 43 connected therewith which are adapted to move in slots 4d!) of the body or housing 4@ so as to limit the relative movement of the slip expander 42 yupwardly with respect to the body 49.

The lower portion of the body 4d has a packing element support ring 44 threaded thereto, and such ring 44 has formed therewith or otherwise suitably connected thereto a packing cup or element 45 which is formed of rubber or other resilient material. Such cup 45 has a lower flared end 45a whereby iluid under pressure from below the cup 45 is adapted to distort or expand the element 45 laterally outwardly into engagement with the inside of the casing C to form a fluid seal therewith. The cup 45 has molded therewith or otherwise suitably connected thereto, a plurality of gripping members 46 which are adapted to move outwardly with the cup 45 as it is distorted under uid pressure.

A similar packing element or cup 48 is provided above the slip expander 42 and is connected thereto by a support ring 49. The cup 48 is, of course, molded or otherwise suitably connected to the ring 49, and additionally gripping members 50 which are similar to the gripping members 46 are molded or otherwise secured to the cup or element 48, whereby upon the application of a uid pressure to the flared end 43a of the packing element or cup 4S, the cup or element 48 is expanded or distorted into a sealing contact with the casing C and also the gripping members 56 are urged into gripping contact with such casing. It will also be observed that when a differential well fluid pressure exists above and below the packer B, the cups 45 and 48 are urged towards each other so as to cause the slip expander 42 to be urged downwardly relative to the slips 41 whereby the slips 41 are maintained in a gripping contact with the pipe or casing C.

The lower support ring 44 is provided with an internal annular recess 44a in which a plurality of internally threaded nut segments 52 are positioned. Each of the segments 52 is arcuate in construct-ion so that when they are positioned in the recess 44a, they form an annular ring or nut which is urged to its minimum diameter by means of a spring 53 which surrounds the segments 52 and applies a constant inward urging force to the segments 52. The segments S2 are movable away from each other against the inward urging of the spring 53, for a purpose to be hereinafter explained. Each of the segments 52 is provided with an upstanding lug 52a which coacts with a lug 40C on the lower end of the body or housing 4t) so as to prevent the relative rotation between the nut segments 52 and the body 40 while permitting lateral or radial movement of the nut segments 52 in the annular recess 44a.

The packer B is initially run into the casing or pipe C and set therein by means of a lowering tool 60 shown in FIGURE 4, having an annular outwardly extending shoulder or ange 61 which is adapted to a seat on the upper surface 5211 of the nut segments 52 to force the packer B downwardly in the well pipe or casing C to position same for setting. Thus, the packer B is maintained in an unset or released condition as it is lowered in the well pipe because the shoulder 61 applies a downward force from the lowering tool 60 to the nut segments 52 which in turn applies a downward force to the housing or slip body 4G to hold the slips 41 in their lowered position. The upper sealing or packing cup 48 is in frictional contact with the inside of the well pipe or casing during such lowering so as to maintain the slip expander 42 in a raised position with the pin or pins 43 at the upper ends of the slots 401;. When the packer B has been positioned at the place in the well bore for setting same above the formation F or other well formation in the well bore, the tool 60 is simply raised upwardly and out of the bore of the packer B so that the packer B is thereafter held against movement in the casing C by the friction springs 47 until the apparatus A is positioned in the casing C, as will be explained.

The operation or use of the apparatus described above and the method of this invention includes the initial positioning of the lower packer D in its set position in the well pipe or casing C. The packer D as previously explained is set in position in a manner similar to that described above in connection with the packer B so as to leave the bore thereof open. The packer D is set above the formation F and below the formation F so as to provide a uid seal therebetween.

After the packer D has been set in the well pipe or casing C, the packer B is lowered into the pipe or casing C and is set therein as previously explained. Preferably such lowering is eected with the lowering pipe 60 illustrated in FIGURE 4. Thereafter, the pipe 60 is removed, leaving the packer B positioned in the casing C in an unset condition with the friction springs 47 supporting same. The bore of the packer B is, of course, larger than the bore of the packer D so that thereafter, upon the lowering of the apparatus A into the well pipe or casing C, the tubing section 36 is adapted to extend through the bore of the packer D so as to form a seal therewith and the pipe 35 is adapted to extend through the bore of the packer B so as to form a seal therewith.

rThe threads 39 on the external surface of the outer pipe 35 slide downwardly relative to the nut segments 52 as the apparatus A is lowered into the bore of the packer B so as to position the threads 39 in threaded engagement with the threads of the nut segments 52. Such inter-engagement of the threads on the nut segments 52 and the threads 39 on the pipe 35 is effected without a rotation of the pipe 35 relative to the nut segments 52 because the threads 39a act to expand or move the segments 52 outwardly during the lowering of the pipe 35 relative to such segments. It should be noted that the friction springs 47 prevent downward movement of the packer B as the nut segments 52 are expanded during the downward sliding of the threads 39 in engagement therewith.

As the apparatus A is thus lowered, the annular shoulder 35C (FIGURE 2B) on the outer pipe 35 seats on the internal annular shoulder 42a of the slip expander 42 to urge same downwardly relative to the slips 41 which are being held against downward movement by the springs 47, so that the slips 41 are set in gripping engagement with the casing C. When the slips 41 are thus set so that the expander 42 can no longer rnove downwardly relative to the slips 41, any further downward movement of the apparatus A relative to the packer B is prevented and at that time, the threads 39 on the pipe 35 and the internal threads on the nut segments 52 are in threaded engagement so as to latch the apparatus A to the packer B. Also, the pipe 36 has passed into and extends through the bore of the packer D so that it establishes fluid communication with the formation F below the packer D and the seals 37 and 3S prevent fluid flow to the area between the cups 45 and 43, whereby a differential in the pressure of the well uid above and below the packer B urges the cups 4S and 48 into an expanded position in sealing contact with the casing C. Although the apparatus A cannot be retrieved by a straight nonrotative upward movement of the apparatus A, upon a rotation of the apparatus A to the right, assuming the threads 39 and the threads on the nut segments 52 are lefthand threads, the body 35 can be disengaged from the nut segments 52 so as to then be movable upwardly relative to the packer B for removal from the well bore or casing C.

Ordinarily, the apparatus A is lowered into the pipe or casing on the tubing string 10, and thereafter, the tubing string 12 is lowered into position after the apparatus A has assumed its seated position in the well bore or casing C (FIGURES 2A and 2B). However, it will be evident that the apparatus A could be lowered on the tubing string 12 and then thereafter the tubing string 10 could be lowered into its connected position. It should be noted that the guide surface 14a at the upper end of the body 14 effects a guiding of the lower end of the tubing string 10 into the bore 16 if the tubing string 10 is the last string to be connected. Similarly, the guide surface 14h guides the lower end of the tubing string 12 into the bore 17 if it is the last string to be connected.

As illustrated in the drawings, the strings 10 and 12 are each connected to the body 14 by automatic bottom-type couplings or connection means. Thus, tubing string 10 is connected by a lowering of the string 10 into the bore 16 until the threads 16a engage with the threads 20a, without requiring any rotation of the tubing string 10. However, to release the tubing string 10 from the nut 20, the tubing string 1t) must be rotated to the right, assuming the threads 10a and 20a are left-hand threads, to effect the release of the string 1t) from the body 14.

The tubing string 12 is connected in the bore 17 by a threaded engagement of the threads 29a with the threads 1711 upon a nonrotative lowering of the string 12 into the bore 17. In order to effect a release of the tubing string 12 from the bore 17, a rotation of the string 12 and the nut 29 is effected to the right, if the threads 29a and 17b are right-hand threads, so as to move the string 12 upwardly and out of the bore 17.

Thus, it can be seen that either of the strings 18 and 12 can be separately connected to the body 14 or disconnected therefrom.

In FIGURE 5, a modified packer B is illustrated for use with a modied well apparatus A. The parts of the modified construction of FIGURE which are the same as the parts of the apparatus shown in FIGURES 2A and 2B have the same numerals. In the device of FIGURE 5, the apparatus A' is identical with that illustrated in FIG- URES 2A and 2B, except that the threads 39 on the outer pipe are omitted in FIGURE 5 and the packer B is maintained in its set position by imposing the weight of the apparatus A and the tubing strings connected therewith on such packer B. The imposition of the tubing weight thus assists the differential well lluid pressure in maintaining the packer B in the set position in the form of the invention shown in FIGURE 5 instead of utilizing the latching of the threads 39 with the nut segments 52 as shown in FIGURE 2B. Similarly, therefore, the packer B is identical with that illustrated in FIGURE 2B, except that the annular members 14d and 144 differ from the members 4@ and 44 of FIGURE 2B by the elimination of the recess 44a for the nut segments 52. Also the internal annular shoulder 152 is provided for Contact by the shoulder 61 of the lowering tool 64b, if such tool 60 is used in positioning the packer B' in the well bore or casing C. The operation of the device shown in FIGURE 5 would, of course, be the same as that explained above in connection with FIGURES 2A and 2B, except that the apparatus A would not have to be rotated to effect the removal thereof from the packer B'.

The foregoing disclosure .and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. A well apparatus adapted to be positioned in a well bore including,

a lower well packer having a longitudinal bore and ancho-red in the well bore between a lower well formation and an upper well formation,

an upper well packer having a longitudinal bore and `anchored in the well bore above said upper well formation,

a body having two longitudinal parallel passages extending therethrough,

a first tubular member depending from the body and adapted to extend into the bore of said upper packer, said tubular member being in fluid communication with one of 'the passages in said body,

sealing means between said first tubular member and the bore of the upper packer,

a second tubular member extending downwardly from the body and through the first tubular member and adapted to extend through the bore of the lower packer, said seco-nd tubul-ar member being in fiuid communication with the other of the passages in the body,

`sealing means between said second tubular member and the bore of the lower packer,

a first tubing string having its lower end insertable within one of the passages of the body,

latch means on said first tubing string and within the passage into which the string inserts for detachably connecting the string to the body, a second tubing string having its iower end insertable within the other of said passages in the body, and latch means on said second tubing string and within the passage into which said second string inserts for detachably `connecting the string to the body.

2. A well apparatus as set `forth in claim 1 wherein,

the latch means which connects the first tubing string to the body is engageable by a straight longitudinal movement of the string into its passage,

means forming pant of said latch means for disengaging said first string from the body upon rotation of the string relative to the body,

the latch means which connects the second tubing string to the body being engageable by a straight line movement of said second string into its passage, and

means forming part of the last-named latch means for disengaging said second string from the body upon rotation of the string relative to the body.

3. A well apparatus ias set forth in claim 1, together with a third latch means mounted with the bore of the upper packer, and

co-acting means formed on the exterior of the iirst tubular member and engageable with said third latch means to connect the first tubular member to the upper packer when said member is in a predetermined position relative thereto.

4. A well apparatus as set forth in claim 1, together with a third latch means mounted with the bore of the upper packer,

co-acting means formed on the exterior of the first tubular member and engageable with said third latch means to connect the first tubular member to the upper packer when -said member is in a predetermined position relative thereto,

said third latch means and the co-acting means effecting `a connection between the first tubular member and the upper packer upon longitudinal movement of the member and packer, and

means forming part of said latch `and co-acting means and actuated by rotation of said first tubular member relative :to the packer to disconnect said rst member from said packer.

References Cited in the file of this patent UNITED STATES PATENTS 1,035,850 Black Aug. 20, 1912 1,861,332 Waltz May 31, 1932 1,871,867 Walker Aug. 16, 1932 2,141,419 Spang Dec. 27, 1938 2,335,355 Penick et ai Nov. 30, 1943 2,368,428 Saurenman Ian. 30, 1945 2,644,524 Baker July 7, 1953 2,691,418 Connolly Oct. 12, 1954 2,739,651 Brown Mar. 27, 1956 

1. A WELL APPARATUS ADAPTED TO BE POSITIONED IN A WELL BORE INCLUDING, A LOWER WELL PACKER HAVING A LONGITUDINAL BORE AND ANCHORED IN THE WELL BORE BETWEEN A LOWER WELL FORMATION AND AN UPPER WELL FORMATION, AN UPPER WELL PACKER HAVING A LONGITUDINAL BORE AND ANCHORED IN THE WELL BORE ABOVE SAID UPPER WELL FORMATION, A BODY HAVING TWO LONGITUDINAL PARALLEL PASSAGES EXTENDING THERETHROUGH, A FIRST TUBULAR MEMBER DEPENDING FROM THE BODY AND ADAPTED TO EXTEND INTO THE BORE OF SAID UPPER PACKER, SAID TUBULAR MEMBER BEING IN FLUID COMMUNICATION WITH ONE OF THE PASSAGES IN SAID BODY, SEALING MEANS BETWEEN SAID FIRST TUBULAR MEMBER AND THE BORE OF THE UPPER PACKER, A SECOND TUBULAR MEMBER EXTENDING DOWNWARDLY FROM THE BODY AND THROUGH THE FIRST TUBULAR MEMBER AND ADAPTED TO EXTEND THROUGH THE BORE OF THE LOWER PACKER, SAID SECOND TUBULAR MEMBER BEING IN FLUID COMMUNICATION WITH THE OTHER OF THE PASSAGES IN THE BODY, SEALING MEANS BETWEEN SAID SECOND TUBULAR MEMBER AND THE BORE OF THE LOWER PACKER, A FIRST TUBING STRING HAVING ITS LOWER END INSERTABLE WITHIN ONE OF THE PASSAGES OF THE BODY, LATCH MEANS ON SAID FIRST TUBING STRING AND WITHIN THE PASSAGE INTO WHICH THE STRING INSERTS FOR DETACHABLY CONNECTING THE STRING TO THE BODY, A SECOND TUBING STRING HAVING ITS LOWER END INSERTABLE WITHIN THE OTHER OF SAID PASSAGES IN THE BODY, AND LATCH MEANS ON SAID SECOND TUBING STRING AND WITHIN THE PASSAGE INTO WHICH SAID SECOND STRING INSERTS FOR DETACHABLY CONNECTING THE STRING TO THE BODY. 